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研究了HfN/HfO_2高K栅结构p型金属-氧化物-半导体(MOS)晶体管(MOSFET)中,负偏置-温度应力引起的阈值电压不稳定性(NBTI)特征.HfN/HfO_2高K栅结构的等效氧化层厚度(EOT)为1·3nm,内含原生缺陷密度较低.研究表明,由于所制备的HfN/HfO_2高K栅结构具有低的原生缺陷密度,因此在p-MOSFET器件中观察到的NBTI属HfN/HfO_2高K栅结构的本征特征,而非工艺缺陷引起的;进一步研究表明,该HfN/HfO2高K栅结构中观察到的NBTI与传统的SiO2基栅介质p-MOSFET器件中观察到的NBTI具有类似的特征,可以被所谓的反应-扩散(R-D)模型表征:HfN/HfO_2栅结构p-MOSFET器件的NBTI效应的起源可以归为衬底注入空穴诱导的界面反应机理,即在负偏置和温度应力作用下,从Si衬底注入的空穴诱导了Si衬底界面Si-H键断裂这一化学反应的发生,并由此产生了Si+陷阱在Si衬底界面的积累和H原子在介质层内部的扩散,这种Si+陷阱的界面积累和H原子的扩散导致了器件NBTI效应的发生.
The characteristics of threshold voltage instability (NBTI) caused by negative bias-temperature stress in HfN / HfO_2 high K gate structure p-type metal-oxide-semiconductor (MOS) The structure has an equivalent oxide thickness (EOT) of 1.3 nm and a low native defect density. Studies have shown that due to the low native defect density of the HfN / HfO 2 high-K gate structure, NBTI belongs to the intrinsic characteristic of HfN / HfO_2 high-K gate structure, not caused by process defects. Further studies show that the NBTI observed in the high-K gate structure of HfN / HfO2 exhibits the same characteristics as the conventional SiO2-based gate dielectric p The NBTI observed in the MOSFET device has similar characteristics and can be characterized by a so-called reaction-diffusion (RD) model: The origin of the NBTI effect of a HfN / HfO 2 gate structure p-MOSFET device can be categorized as the substrate-induced hole-induced The interface reaction mechanism, that is, the hole injected from the Si substrate induces the chemical reaction that the Si-H bond breaks at the Si substrate interface due to the negative bias and the temperature stress, and the Si + trap is generated in the Si The accumulation of substrate interface and the diffusion of H atoms inside the dielectric layer, the interface area of this Si + trap And H atom diffusion occurs as a result of the NBTI effect device.